This invention relates to a method and apparatus for mounting and removing a hub from a shaft. More specifically the invention concerns utilization of a cylinder and a piston provided in an arrangement that may be used in one orientation to force a hub on the shaft and in a separate orientation to remove the hub from the shaft.
In the rotary machine art it is common practice to move a hub of a coupling, impeller or the like onto a shaft over which the hub has been preliminarily applied or to displace a hub from such a mounted position. Numerous types of apparatus have been used to accomplish this function.
Typical of the prior art over which this idea is an improvement is U.S. Pat. No. 3,772,759. This prior art patent discloses a device wherein hydraulic fluid is supplied to expand a chamber to force a hub onto a shaft. Some means for securing the device relative to the shaft such that the expansion force may be used to force the hub onto the shaft is provided. However to use the same apparatus to remove the hub from the shaft requires additional structure for securing the expansion apparatus to the hub. As can be seen in this patent the additional structure includes longitudinally extending rods which are secured internally within the hub. These rods are connected to a separate structure against which the expansion portion must be mounted.
The herein device utilizes a cylinder and a piston which may be mounted in a first position with the cylinder secured to the shaft such that upon the application of pressurized fluid the piston is displaced forcing the hub on the shaft similar to the prior art. However to effect removal of the hub from the shaft the assembly is simply reversed and placed in the opposite direction with the cylinder abutting the shaft and with the piston threadably engaged on its exterior surface to an interior surface of the coupling. Pressurized fluid may then be supplied to the cavity to effect displacement of the hub to remove it from the shaft.